ethdev: remove jumbo offload flag

[dpdk.git] / doc / guides / nics / bnxt.rst

diff --git a/doc/guides/nics/bnxt.rst b/doc/guides/nics/bnxt.rst
index 0fb2032..aa60328 100644 (file)
--- a/doc/guides/nics/bnxt.rst
+++ b/doc/guides/nics/bnxt.rst
@@ -77,7 +77,7 @@ It can direct some traffic, for example data plane traffic, to DPDK.
 Rest of the traffic, for example control plane traffic, would be redirected to
 the traditional Linux networking stack.
 
-Refer to https://doc.dpdk.org/guides/howto/flow_bifurcation.html
+Refer to :doc:`../howto/flow_bifurcation`
 
 Benefits of the flow bifurcation include:
 
@@ -658,8 +658,7 @@ which currently supports basic packet classification in the receive path.
 The feature uses a newly implemented control-plane firmware interface which
 optimizes flow insertions and deletions.
 
-This is a tech preview feature, and is disabled by default. It can be enabled
-using bnxt devargs. For ex: "-a 0000:0d:00.0,host-based-truflow=1”.
+This is a tech preview feature.
 
 This feature is currently supported on Whitney+ and Stingray devices.
 
@@ -853,48 +852,58 @@ DPDK implements a light-weight library to allow PMDs to be bonded together and p
 Vector Processing
 -----------------
 
+The BNXT PMD provides vectorized burst transmit/receive function implementations
+on x86-based platforms using SSE (Streaming SIMD Extensions) and AVX2 (Advanced
+Vector Extensions 2) instructions, and on Arm-based platforms using Arm Neon
+Advanced SIMD instructions. Vector processing support is currently implemented
+only for Intel/AMD and Arm CPU architectures.
+
 Vector processing provides significantly improved performance over scalar
-processing (see Vector Processor, here).
+processing. This improved performance is derived from a number of optimizations:
+
+* Using SIMD instructions to operate on multiple packets in parallel.
+* Using SIMD instructions to do more work per instruction than is possible
+  with scalar instructions, for example by leveraging 128-bit and 256-bi
+  load/store instructions or by using SIMD shuffle and permute operations.
+* Batching
 
-The BNXT PMD supports the vector processing using SSE (Streaming SIMD
-Extensions) instructions on x86 platforms. It also supports NEON intrinsics for
-vector processing on ARM CPUs. The BNXT vPMD (vector mode PMD) is available for
-Intel/AMD and ARM CPU architectures.
+    * TX: transmit completions are processed in bulk.
+    * RX: bulk allocation of mbufs is used when allocating rxq buffers.
 
-This improved performance comes from several optimizations:
+* Simplifications enabled by not supporting chained mbufs in vector mode.
+* Simplifications enabled by not supporting some stateless offloads in vector
+  mode:
 
-* Batching
-    * TX: processing completions in bulk
-    * RX: allocating mbufs in bulk
-* Chained mbufs are *not* supported, i.e. a packet should fit a single mbuf
-* Some stateless offloads are *not* supported with vector processing
-    * TX: no offloads will be supported
-    * RX: reduced RX offloads (listed below) will be supported::
+    * TX: only the following reduced set of transmit offloads is supported in
+      vector mode::
+
+       DEV_TX_OFFLOAD_MBUF_FAST_FREE
+
+    * RX: only the following reduced set of receive offloads is supported in
+      vector mode (note that jumbo MTU is allowed only when the MTU setting
+      does not require `DEV_RX_OFFLOAD_SCATTER` to be enabled)::
 
        DEV_RX_OFFLOAD_VLAN_STRIP
        DEV_RX_OFFLOAD_KEEP_CRC
-       DEV_RX_OFFLOAD_JUMBO_FRAME
        DEV_RX_OFFLOAD_IPV4_CKSUM
        DEV_RX_OFFLOAD_UDP_CKSUM
        DEV_RX_OFFLOAD_TCP_CKSUM
        DEV_RX_OFFLOAD_OUTER_IPV4_CKSUM
+       DEV_RX_OFFLOAD_OUTER_UDP_CKSUM
        DEV_RX_OFFLOAD_RSS_HASH
        DEV_RX_OFFLOAD_VLAN_FILTER
 
-The BNXT Vector PMD is enabled in DPDK builds by default.
-
-However, a decision to enable vector mode will be made when the port transitions
-from stopped to started. Any TX offloads or some RX offloads (other than listed
-above) will disable the vector mode.
-Offload configuration changes that impact vector mode must be made when the port
-is stopped.
+The BNXT Vector PMD is enabled in DPDK builds by default. The decision to enable
+vector processing is made at run-time when the port is started; if no transmit
+offloads outside the set supported for vector mode are enabled then vector mode
+transmit will be enabled, and if no receive offloads outside the set supported
+for vector mode are enabled then vector mode receive will be enabled.  Offload
+configuration changes that impact the decision to enable vector mode are allowed
+only when the port is stopped.
 
 Note that TX (or RX) vector mode can be enabled independently from RX (or TX)
 vector mode.
 
-Also vector mode is allowed when jumbo is enabled
-as long as the MTU setting does not require scattered Rx.
-
 Appendix
 --------